USE OF LOW TOXICITY ADJUVANTS AND KILLED VIRUS TO INDUCE PROTECTIVE IMMUNITY AGAINST THE FRIEND MURINE LEUKEMIA RETROVIRUS-INDUCED DISEASE

Low toxic and synthetic adjuvants were investigated in the induction o f protective immunity against Friend murine retrovirus-induced erythro leukaemia by immunization with inactivated Friend murine leukaemia hel per virus (F-MuLV). adecanoyl)-N-acetylmuramyl-L-alanyl-D-isoglutamine (B30-MDP) showed a significant enhancement of the protective immunity against Friend virus-induced erythroleukaemia not only in H-2a/b mice known to make good immune responses to F-MuLV envelope, but also in H -2a/a mice which are usually unable to respond to F-MuLV envelope prot ein. Another analogue of N-acetylmuramyl-D-isoglutamine (MDP), lanyl-D -isoglutaminyl-N(epsilon)-stearoyl-L-lysine [MDP-Lys(L18)], which has been shown to enhance non-specific protective activity against bacteri al and viral infections, however, showed no adjuvant activity in the p resent system. A combined adjuvant of the synthesized mycobacterial co rd factor, trehalose dimycolate (TDM) and detoxified bacterial endotox in, monophosphoryl lipid A from Salmonella minnesota, gave good protec tion which was comparable to complete Freund's adjuvant in both H-2a/b and H-2a/a mice.